Compliance with environmental regulations at facilities equipped with dry or semi-dry FGD processes requires removal of particulate matter from the flue gas at a location between the FGD process and emission point. The particulate matter entrained in the flue gas at this location typically consists of solid by-products of the combustion and FGD process including fly ash, partially-burned fuel, and various compounds of sulfur, chlorine, calcium and sodium.
Many dry or semi-dry FGD systems include “reverse air” type fabric filters to remove particulate matter. Reverse air type fabric filters typically utilize multiple cylindrical filter bag assemblies, each comprised of a fine mesh filter fabric with an integral metal filter cap. The metal filter cap encloses the top end of the filter bag, thereby enabling the assembly to be suspended vertically within the bag house compartment. In the prior art, corrosion and subsequent failure of the filter cap typically causes irreparable filter bag damage, excessive particulate matter emission, unplanned decreases in power plant output, and excessive maintenance costs. Moreover, replacement of the integral filter cap (as a preventive maintenance action) typically necessitates replacement of the entire filter bag assembly, thereby adding to corrective maintenance costs.
Therefore, there is a need in the art for an alternative suspendable filter bag device that is corrosion resistant and replaceable independently of the filter bag. There is also a need for a filter bag and suspension system which is durable, economical and requires less maintenance.